1. Field of the Disclosure
This disclosure relates generally to semiconductors, and more specifically, to data processors that implement a debug mode of operation.
2. Description of the Related Art
An IEEE standard known as IEEE ISTO5001, or the Nexus debug standard, is an established real-time debug standard that supports real-time debug message generation. The Nexus debug standard specifies a mechanism for identifying to an external trace reconstruction tool a predetermined operating condition within the system. Debugging processes are also used in the development of code for a data processing system. Providing debug information in real-time, without intrusion on the normal operation of the data processing system, is highly desirable to remain transparent to operation of the system.
Debug messages include trace messages that are generated by the data processing system. Trace messages can contain address and data information for either program events (program trace messaging) that relate to the execution sequence of instructions, or for data events (data read/write messaging) that relate to the access of information based upon the execution of instructions. The address information is typically virtual address information that must be translated to identify a physical memory location known as a physical address. An issue arises when the amount of trace messaging information overruns buffer space used to store the trace messages prior to being transmitted to a debug tool.